serial: pl011: Fix oops on -EPROBE_DEFER

If probing of a pl011 gets deferred until after free_initmem(), an oops
ensues because pl011_console_match() is called which has been freed.

Fix by removing the __init attribute from the function and those it
calls.

Commit 10879ae5f12e ("serial: pl011: add console matching function")
introduced pl011_console_match() not just for early consoles but
regular preferred consoles, such as those added by acpi_parse_spcr().
Regular consoles may be registered after free_initmem() for various
reasons, one being deferred probing, another being dynamic enablement
of serial ports using a DeviceTree overlay.

Thus, pl011_console_match() must not be declared __init and the
functions it calls mustn't either.

Stack trace for posterity:

Unable to handle kernel paging request at virtual address 80c38b58
Internal error: Oops: 8000000d [#1] PREEMPT SMP ARM
PC is at pl011_console_match+0x0/0xfc
LR is at register_console+0x150/0x468
[<80187004>] (register_console)
[<805a8184>] (uart_add_one_port)
[<805b2b68>] (pl011_register_port)
[<805b3ce4>] (pl011_probe)
[<80569214>] (amba_probe)
[<805ca088>] (really_probe)
[<805ca2ec>] (driver_probe_device)
[<805ca5b0>] (__device_attach_driver)
[<805c8060>] (bus_for_each_drv)
[<805c9dfc>] (__device_attach)
[<805ca630>] (device_initial_probe)
[<805c90a8>] (bus_probe_device)
[<805c95a8>] (deferred_probe_work_func)

Fixes: 10879ae5f12e ("serial: pl011: add console matching function")
Signed-off-by: Lukas Wunner <[email protected]>
Cc: [email protected] # v4.10+
Cc: Aleksey Makarov <[email protected]>
Cc: Peter Hurley <[email protected]>
Cc: Russell King <[email protected]>
Cc: Christopher Covington <[email protected]>
Link: https://lore.kernel.org/r/f827ff09da55b8c57d316a1b008a137677b58921.1597315557.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <[email protected]>

0 files changed, 0 insertions, 0 deletions